Automatic stoker



Nov., 23, 1948. VL T. NORMAN ATouATIc s'rolcsn 3 Sheets-Sheet 1 Filed Feb. 28, 1945 46H P/r c2544/ ar we Joseph 7/Vorm144 Gual/swg.

Nov. 23, 1948. v J. T. NORMAN 2,454,400

AUTOMATIC STOKER Filed Feb. 28,1945 heats-sheet 2 Bmw.

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AUTOIATIC-STOKER -Filed Feb. 28, 1945 y 3 Sheets-Sheet 3 g 33? me oAMPER 24J/1 PIT' CLEA/V 007' 000e nmwnhm Jaepz; IFA/arman,

Patented Nov. 23, 1

UNITED TiES PATENT OFFICE AUTOMATIC STOKER Joseph T. Norman, Huntington Mills, Pa.

ApplicationFebrnary 28, 1945, Seria! No. 580,149 9 Claims. (Cl. 11B-29) My invention relates to self-staking furnaces and it particularly relates to the mechanism for delivering and feeding the fuel to the fire as needed and causing discharge of the ash and clinlrers under pressure.

An object of my present invention lsvto provide a stoker which will burn any and all usual sizes of coal and also will burn wood in logs or other shapes.

Again it is an object to provide a self-stoking furnace that, especially when coal is the fuel used, will operate on natural draft, although I prefer to use a. suction blower or fan in the connection betweenthe furnace and the chimney and control the same and the stoking motor by use of any of the known thermostat regulators.

Other objects will in part be obvious and in part bepointed out hereinafter.

To the attainment of the aforesaid objects and ends the invention further resides in `those novel details of construction. combination and arrangement`of parts all of which will be first fully described and then be specifically pointed out in the appended claims, reference being had to the accompanying drawings in which:

Fig. 1 is a vertical cross section of one embodiment of my invention, taken on the line 1-1 of Fig. 2,

Fig. 2 is a front elevation on a reduced scale of the structure shown in Fig. 1.

Fig. 3 is a View similar to Fig. 1 showing a second embodiment of my invention.

Fig. 4 is a vertical section. on aI reduced scale, on the line 4-4 of Fig. 3.

Fig. 5 is a view similar to Fig. 1 showing the inventionadapted toa hot air furnace.

In the drawings in which like numerals and letters of reference indicate like parts in all the figures, I indicates the shell or housing of the heating chamber H, and 2 indicates the bottom thereof. The shell Ivis provided with outlets 3 to which the hot water conduits to the radiators (not shown) are coupled, the return flow conduits (not shown) being connected to inlet nipples 43.

Passing through the front wall and the bottom of the shell l is an arcuate (preferably about semi-circular in vertical section) fire box 4, the entrance to which is at the top and the exit end of which is at the bottom. The cross-sectional area of the nre box. preferably, progressively increases from the entrant to the exit end. The

re box'Ii has ue outlets 5 for smoke and other.

products of combustion, from which outlets ducts 6 extend upwardlyto a header 1 from which a pipe Y8 passes through-the top of the shell I and connects to the chimney. preferably via a suction blower or fan, not shown. The header 'i has clean-out doors 1X. The fire box 4 has an opening 3 normally closed by a suitable door 9X (see Figs. 1 and 4) through which the fire may be lighted.

At the lower end of the fire box is an approximately vertically disposed hinged grate i0 which is either weight-loaded as in Fig. 1 or it may be spring loaded as in Fig. 3.

A spiral rotary grate II is disposed at the bottom of the fire box adjacent the grate I i) and is slowly turned by means of a pawl I8 and ratchet I4, the pawl I B being carried by a rocking lever Iii pivoted on the shaft I3 of the grate I I and operated by-a crank disc 24 and connecting rod 25. A backing grate I2 is located behind the rotary grate. The rotary grate may be dispensed with if desired (see Fig. 3 for instance).

The crank discA 24 is carried on a stub shaft 2i Journalled in a bearing 22 (see Fig. 2), and driven by a sprocket and chain connection 23 to the electric motor M that is mounted on the shelf 43.

The motor M also drives via a sprocket and chain connection 20, a shaft I1 mounted in bearings I 8 and carrying'two crank discs I9 to which connecting rods 30 are pivoted,v the rods 30 also bein-g pivoted to brackets 28 on a carriage 21 whose wheels 28 run in tracks 26 formed of channel irons. The carriage 21 has slots 3i in its front end 32 through which the arms 33.c of alU-shaped spring loaded pusher 33 slide. Stops 34 prevent the springs 35 from pushing out the member 33 too far. A plate 38 lies beneath the pusher so that when the carriage is retracted fuel will drop, through the throat 31X of the hopper 31, in front of the pusher 33.

A suitable draft regulator 38 admits air into the ash pit A to be drawn up through the nre bed to support combustion and a suitable 'cleanout 41 for the ash pit A is also provided.

When wood is the fuel used the logs, properly cut to lengths, are placed in the hopper 31 as indicated at W in Fig. 1 andare forced down into the fire box 4 by the reciprocations of the ing chamber and a fire box, 'said fire box being burning coal principally. although, it can also be used to burn comminuted wood or wood in small enough pieces to compare with coal sizes. In these ngures the boiler is shown as a steam boiler.

In Figs. 3 and 4 those parts which correspond to and areA substantially the same as like parts in Figs. l and 2 bear the same reference number or letter plus the index letter a. In this embodiment of my invention the upper end of the fire box 4a communicates with a worm housing 40 (which may be formed integrally with the fire i box walls) in which is a worm 4| that feeds the fuel the full length ci the furnace. The worm 4| has a shaft 42 and may be of substantially the same construction as the worm i of my Pat ent #2,355,101 issued August 8, 1944.

In the embodiment of Fig. 3 the rotary grate is dispensed with and only a hinged, vertical grate I is used. This grate i0 is mounted on a wall 4Q which also has a bearing through which a rod 48 passes. One end of this rod is secured to the grate I0 and the other end is spring-loaded. as at 4l.

A motor M* drives the worm 4I via a belt and pulley or sprocket and chain drive 43. The hopper 38 delivers the coal C to one end of the worm 4|.

The worm carries the coal across the furnace and delivers it into the entrant end of the nre box with sumclent force to force the fuel and ashes down the curved way and effect discharge of the ashes as indicated in Fig. 3.

In Fig. 3 a water level gage 50 is employed.

When the invention is applied to a'hot air furnace an air inlet BI is provided in which a fan 52 is located to force air into the furnace as shown in Fig. 5. In this gure those parts which correspond to like parts in the preceding figures bear the same reference nunber plus the index letter b.

It will be noted that in all embodiments of my invention the nre box 4 is of gradually increasing cross-sectional area from the top or entrant end to the bottom or exit end. This prevents choking the passage by fuel and ash.

The action of the motors M, M* and Mb may be controlled by any suitable thermostatic heat regulator but as the same is not, part of my invention, I .have not disclosed same in this specification and the accompanying drawings. Also any suitable speed reducer (not shown) may be used with the motors.

From the foregoing description taken in connection with the accompanying drawings it is thought theY construction, operation and advantages of the invention will be clear to those skilled in the art.`

A Whatlclaimis:

l. A furnace having a shell enclosing a heating chamber and a fire box, said fire box being fixedly held and having an entrance at one side of the shell and extending inwardly therefrom and curved downwardly, said fire box at a location between its ends having flue openings; ducts within the heating chamber and connected to said fire box at each nue opening; a header within said heating chamber into which said ducts deliver products of combustion and an off-take duct from the header to -the outside of the heating chamber; an upright grate at the outlet end of said fire box, means for forcing fuel into and along said fire box and expelling ashes from the same, and means to admit air to the exit end of said nre box for combustion purposes.

2. A furnace having a shell enclosing a heatnxedly held and having an entrance at one side of the shell and extending inwardly therefrom and curved downwardly, said fire box at a location between its ends having i'iue openings: ducts .within the heating chamber and connected yto said fire box at each flue opening; a header within said heating chamber into which said ducts deliver products of combustion and an o-take duct from the header to the outside of the heating chamber: an upright grate at the outlet end of said fire box, means for forcing fuel into and along said f'ire box and expelling ashes from the same, and means to admit air to the exit end of said fire box for combustion purposes, said fuel forcing means comprising a fuel hopper and means for taking fuel from the hopper and forcing it into the top end of the fire box.

3. In self-staking furnace: the improvement which includes a shell enclosing a fluid chamber and a heating chamber within which heating chamber is a fixedly held fire box composed of an approximately semi-circular duct having at least one flue opening intermediate its entrant and exit ends, a duct from said flue opening through said heating chamber to the outside of the same, means for intermittently forcing fuel into the entrant end of vand through said fire box duct and forcing the ashes from the exit end of the fire box duct, a vertical grate at the exit end of the fire box, means for admitting air for comibustion to the fuel in the fire box, and a heatin fluid ofltake duct from said shell.

4. In a self-stoking furnace the improvement u which comprises a fxedly held vertically disposed semicircular duct nre box having both its entrant end and its exit end disposed at the same side of the furnace with the entrant end uppermost, said fire box intermediate its ends having at least one flue opening. a duct from said opening for the escape of products of combustion, means for forcing fuel through said fire Ibox from its entrant end toward its exit end and past said flue, and a vertical grate and a rotary grate means at the exit end of said fire box.

5. In a self-staking furnace the improvement which comprises a xedly heid vertically disposed semi-circular duct flre box having both its entrant end and its exit end disposed at the same side of the furnace with the entrant end uppermost, said fire box intermediate its ends having at least one flue opening, a duct from said opening for the escape of products of combustion, means for forcing fuel through said nre box from its entrant end toward its exit end and past said flue, rotary grate means at the exit end of said fire box, and means for admitting air to the grate end of said fire box for combustion purposes.

6. In a self-stoking furnace the improvement which comprises a fixedly held vertically disposed semi-circular duct fire box having both its entrant end and its exit end disposed at the same side of the furnace with the entrant end uppermost, said fire box intermediate its ends having at least one flue opening, a duct from said opening for the escape of products of combustion, means for forcing fuel through said fire box from its entrant end toward its exit end and past said flue, grate means at the exit end of said fire box, and means for admitting air to the grate end of said fire box for combustion purposes, said grate means comprising a pivoted vertically disposed bar-grate, a rotary grate adjacent to said bargrate and a i'ixed bar-grate adjacent said rotary grate on the side opposite said pivoted bar-grate.

7. n a self-stoking furnace: the improvement which includes a shell enclosing a heating chamber within which is a fixediy held fire box composed of an approximately semi-circular duct having at least one flue opening intermediate its entrant and exit ends, a duct from said flue opening through said heating chamber to the outside of the same, means for intermittently forcing fuel into the entrant end of and through said re box duct and forcing the ashes from the exit.end of the re box duct, a grate at the exit end of the fire box, means for admitting air for combustion to the fuel in the fire box, said shell having an outlet adjacent its top for connection to heat ducts and having an air inlet adjacent its bottom, and .means for blowing air into said shell through said air inlet.

8. A furnace having a shell` enclosing a heating chamber, an ash receiving chamber, and a semi-circular fire box having an entrant end at one side of said shell and an exit end adjacent and directed toward the same side of the shell as that in which the entrant end is located, said fire box at a suitable location between its ends having flue openings; ducts within said shell connected to said fire box in register with said flue openings; an offtake flue for said ducts to the outside of the casing; means for positively creating a suction in said oitake flue; a grate at the outlet end of said fire box; a fuel hopper; and means for conducting fuel from said fuel hopper to the entran-tend of said fire box and forcing the fuel past said flue openings.

9. A -furnace having a shell enclosing a heating chamber, an ash receiving chamber, and a semicircular fire box having an entrant end at one side of said shell and an exit end adjacent and directed l0 forcibly feeding fuel from said fuel hopper into and through said fire box and simultaneously forcing the ashes out of the same.

JOSEPH T. NORMAN.

15 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5.30 Number Name Date 182,057 Bonta Sept. 12, 1876 836,402 Politz Nov. 20, 1906 1,368,701 Coulston "Feb, 15, 1921 1,570,604 Aram Jan. 26, 1926 2:, 1,578,546 Myers Mar. 30, 1926 1,605,449 Masonick Nov. 2, 1926 1,636,375 Lundgren July 19, 1927 1,886,064 Steinmuller Nov. 1, 1932 2,123,163 Blrkenbeuel July 12, 1938 30 2,228,758 Drummond Jan. 14,v 1941 FOREIGN PATENTS Number Country Date 44,169 Germany Aug. 10, 1888 3,-, `620,704 Germany Oct. 25, 1935 toward the same side of the shell as that in which the entrant end islocated, said fire box at a suitable location between its ends having flue openings; ducts within said shell connected to said nre .box in register with said flue openings; an offtake flue for said ducts to the outside of the casing; means for Apositively creating a suction in said oiItake flue; a grate at the outlet end of said fire box; a fuel hopper; and means for Germany Oct. 15, 1940 

